U.S. patent application number 12/059198 was filed with the patent office on 2009-10-01 for multi-cavity electromagnetic shielding device.
This patent application is currently assigned to Universal Scientific Industrial Co.Ltd.. Invention is credited to Chih-Hsien Chiu, Kuan-Hsing Li.
Application Number | 20090244876 12/059198 |
Document ID | / |
Family ID | 41116902 |
Filed Date | 2009-10-01 |
United States Patent
Application |
20090244876 |
Kind Code |
A1 |
Li; Kuan-Hsing ; et
al. |
October 1, 2009 |
MULTI-CAVITY ELECTROMAGNETIC SHIELDING DEVICE
Abstract
An electromagnetic shielding device includes a metal frame
mounted on a circuit board and having a looped surrounding wall
configured with an inner space divided into first and second space
portions by a partition wall unit. A cover is mounted fittingly
into the inner space in the metal frame, and includes a dielectric
cover body, and a conductive material layer attached to an outer
surface of the cover body. The cover body has a looped surrounding
wall extending downwardly from a periphery of a top wall and
disposed in proximity to the looped surrounding wall of the metal
frame such that the conductive material layer is in electrical
contact with the looped surrounding wall of the metal frame. The
cover cooperates with the metal frame to define first and second
cavities having different depths and corresponding respectively to
the first and second space portions.
Inventors: |
Li; Kuan-Hsing; (Taichung
City, TW) ; Chiu; Chih-Hsien; (Changhua City,
TW) |
Correspondence
Address: |
VEDDER PRICE P.C.
222 N. LASALLE STREET
CHICAGO
IL
60601
US
|
Assignee: |
Universal Scientific Industrial
Co.Ltd.
Tsao-Tun Chen
TW
|
Family ID: |
41116902 |
Appl. No.: |
12/059198 |
Filed: |
March 31, 2008 |
Current U.S.
Class: |
361/818 |
Current CPC
Class: |
H05K 9/0032
20130101 |
Class at
Publication: |
361/818 |
International
Class: |
H05K 9/00 20060101
H05K009/00 |
Claims
1. An electromagnetic shielding device adapted to be disposed on a
circuit board, comprising: a metal frame adapted to be mounted on
the circuit board and including a looped surrounding wall
configured with an inner space, and a partition wall unit connected
to said looped surrounding wall for dividing said inner space into
at least first and second space portions; and a cover mounted
fittingly into said inner space in said metal frame, and including
a dielectric cover body having an outer surface, and a conductive
material layer attached to said outer surface of said dielectric
cover body, said cover body having a top wall, and a looped
surrounding wall extending downwardly from a periphery of said top
wall and disposed in proximity to said looped surrounding wall of
said metal frame such that the conductive material layer is in
electrical contact with said looped surrounding wall of said metal
frame, said cover cooperating with said metal frame so as to define
at least first and second cavities corresponding respectively to
said first and second space portions of said inner space in said
metal frame, said first and second cavities having different
depths.
2. The electromagnetic shielding device as claimed in claim 1,
wherein: said looped surrounding wall of said metal frame has a
looped inner surface formed integrally with a plurality of
protrusions that are spaced apart from each other; and said looped
surrounding wall of said cover body of said cover has a bottom end
formed with a plurality of notches that are spaced apart from each
other and that engage respectively said protrusions.
3. The electromagnetic shielding device as claimed in claim 2,
wherein each of said notches is defined by an inverted U-shaped
surface, said conductive material layer being further attached to
said inverted U-shaped surfaces of said looped surrounding wall of
said cover body such that said conductive material layer is further
in electrical contact with said protrusions of said looped
surrounding wall of said metal frame.
4. The electromagnetic shielding device as claimed in claim 1,
further comprising a conductive glue attached between a top end of
said looped surrounding wall of said metal frame and said
conductive material layer of said cover.
5. The electromagnetic shielding device as claimed in claim 1,
wherein said partition wall unit of said metal frame includes a
partition wall.
6. The electromagnetic shielding device as claimed in claim 5,
wherein: said partition wall of said metal frame has a top end
formed integrally with a plurality of positioning pins that are
spaced apart from each other; and said top wall of said cover body
of said cover is formed with a plurality of positioning holes that
are spaced apart from each other and that engage fittingly and
respectively said positioning pins of said partition wall of said
metal frame.
7. The electromagnetic shielding device as claimed in claim 6,
wherein each of said positioning holes is defined by an annular
inner surface, said conductive material layer being further
attached to said annular inner surfaces of said top wall of said
cover body such that said conductive material layer is further in
electrical contact with said positioning pins of said partition
wall of said metal frame.
8. The electromagnetic shielding device as claimed in claim 7,
further comprising a conductive glue attached to said conductive
material layer of said cover, disposed on a top end of each of said
positioning pins, and covering a corresponding one of said
positioning holes in said top wall of said cover body.
9. The electromagnetic shielding device as claimed in claim 6,
wherein said top wall of said cover body of said cover has a
horizontal first wall portion, a horizontal second wall portion,
and an inclined third wall portion having an upper end connected to
one end of said first wall portion, and a lower end connected to
one end of said second wall portion, the depth of
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an electromagnetic shielding
device, more particularly to a multi-cavity electromagnetic
shielding device.
[0003] 2. Description of the Related Art
[0004] FIGS. 1 and 2 illustrate an electronic device employing a
conventional electromagnetic shielding device that includes a metal
frame 1 and a metal cover 2. The metal frame 1 is mounted on a
circuit board 3 via a looped solder pad unit 31 using surface
mounting techniques. The circuit board 1 is mounted with first and
second electronic component units 301, 302 that are spaced apart
from each other, wherein the first electronic component unit 301
has a height greater than that of the second electronic component
unit 302. The metal frame 1 has a looped surrounding wall
configured with an inner space 103 that is divided by a partition
wall 12 into a first space portion 101 for receiving the first
electronic component unit 301, and a second space portion 102 for
receiving the second electronic component unit 302. The metal cover
2 is mounted on the circuit board 3, and covers the metal frame 2.
The metal cover 2 has a top wall 201 disposed on a top side of the
metal frame 1, and a looped surrounding wall 202 extending
downwardly from a periphery of the top wall 201 and disposed in
proximity to the looped surrounding wall 11 of the metal frame 1
such that the metal frame 1 cooperates with the metal cover 2 so as
to define first and second cavities corresponding respectively to
the first and second space portions 101, 102.
[0005] It is noted that, since the metal cover 2 is formed by
pressing, it is difficult to fabricate the metal cover having
various thicknesses, and various heights relative to the circuit
board 3. As a result, even though the heights of the first and
second electronic component units 301 and 302 are different, the
metal cover 2 of the conventional electromagnetic shielding device
has a uniform height (h), such as 2 mm, and a thickness ranged from
0.15 mm to 0.2 mm. Therefore, the electronic device employing the
conventional electromagnetic shielding device has a relatively
large size, thereby impeding miniaturization of the electronic
device.
SUMMARY OF THE INVENTION
[0006] Therefore, the object of the present invention is to provide
a multi-cavity electromagnetic shielding device that can overcome
the aforesaid drawbacks of the prior art.
[0007] According to one aspect of the present invention, there is
provided an electromagnetic shielding device adapted to be disposed
on a circuit board. The electromagnetic shielding device
comprises:
[0008] a metal frame adapted to be mounted on the circuit board and
including a looped surrounding wall configured with an inner space,
and a partition wall unit connected to the looped surrounding wall
for dividing the inner space into at least first and second space
portions; and
[0009] a cover mounted fittingly into the inner space in the metal
frame, and including a dielectric cover body having an outer
surface, and a conductive material layer attached to the outer
surface of the dielectric cover body, the cover body having a top
wall, and a looped surrounding wall extending downwardly from a
periphery of the top wall and disposed in proximity to the looped
surrounding wall of the metal frame such that the conductive
material layer is in electrical contact with the looped surrounding
wall of the metal frame, the cover cooperating with the metal frame
so as to define at least first and second cavities corresponding
respectively to the first and second space portions of the inner
space in the metal frame, the first and second cavities having
different depths.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other features and advantages of the present invention will
become apparent in the following detailed description of the
preferred embodiments with reference to the accompanying drawings,
of which:
[0011] FIG. 1 is a partly exploded perspective view of an
electronic device employing a conventional electromagnetic
shielding device;
[0012] FIG. 2 is a schematic sectional view of the electronic
device employing the conventional electromagnetic shielding
device;
[0013] FIG. 3 is a partly exploded perspective view showing an
electronic device employing the first preferred embodiment of an
electromagnetic shielding device according to the present
invention;
[0014] FIG. 4 is an assembled perspective view showing the
electronic device employing the first preferred embodiment;
[0015] FIG. 5 is a schematic sectional view showing the electronic
device employing the first preferred embodiment of an
electromagnetic shielding device according to the present
invention; and
[0016] FIG. 6 is a schematic sectional view showing an electronic
device employing the second preferred embodiment of an
electromagnetic shielding device according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Before the present invention is described in greater detail,
it should be noted that like elements are denoted by the same
reference numerals throughout the disclosure.
[0018] Referring to FIGS. 3 to 5, the first preferred embodiment of
an electromagnetic shielding device according to the present
invention is shown to be embodied in an electronic device. The
electronic device includes a rectangular circuit board 100, and
first and second electronic component units 110, 120 mounted on the
circuit board 100 and spaced apart from each other. The first
electronic component unit 110 has a height greater than that of the
second electronic component unit 120. The electromagnetic shielding
device is adapted to be disposed on the circuit board 100, and
includes a metal frame 10 and a metal cover 20.
[0019] The metal frame 10 is adapted to be mounted on the circuit
board 100 via a looped solder pad unit 130, which is attached to
the circuit board 100, using surface mounting techniques. The metal
frame 10 includes a looped surrounding wall 11 and a partition wall
unit. The looped surrounding wall 11 is configured with an inner
space 13, and has a looped inner surface 112 formed integrally with
a plurality of protrusions 113 that are spaced apart from each
other. In this embodiment, the partition wall unit includes a
partition wall 12 connected to the looped surrounding wall 11 for
dividing the inner space 13 into first and second space portions
131, 132. The partition wall 12 has a top end 121 formed integrally
with a plurality of positioning pins 122 that are spaced apart from
each other.
[0020] The cover 20 is mounted fittingly into the inner space 13 in
the metal frame 10, and includes a dielectric cover body 21 and a
conductive material layer 22. The cover body 21 is made of a
plastic material, is formed by injection molding, and has an outer
surface. The conductive material layer 22 is made of metallic
paint, and is attached to the outer surface of the cover body 21.
The cover body 21 has a top wall 23, and a looped surrounding wall
24 extending downwardly from a periphery of the top wall 23 and
disposed in proximity to the looped surrounding wall 11 of the
metal frame 10 such that the conductive material layer 22 is in
electrical contact with the looped surrounding wall 11 of the metal
frame 10, as shown in FIG. 5. The cover 20 cooperates with the
metal frame 10 so as to define first and second cavities 40, 50
corresponding respectively to the first and second space portions
131, 132 in the metal frame 10. The depth of the first cavity 40 is
greater than that of the second cavity 50. In this embodiment, the
looped surrounding wall 24 of the cover body 21 has a bottom end
241 formed with a plurality of notches 242 that are spaced apart
from each other and that engage respectively the protrusions 113 of
the metal frame 10. Each notch 242 is defined by an inverted
U-shaped surface 243. It is noted that the conductive material
layer 22 is further attached to the inverted U-shaped surfaces 243
of the looped surrounding wall 24 of the cover body 20 such that
the conductive material layer 22 is further in electrical contact
with the protrusions 113 of the metal frame 10. In addition, the
top wall 23 of the cover body 21 has a uniform thickness ranged
from 0.13 mm to 0.15 mm, a horizontal first wall portion 231, a
horizontal second wall portion 232, and an inclined third wall
portion 233 having an upper end connected to one end of the first
wall portion 231, and a lower end connected to one end of the
second wall portion 232 such that a distance (h1) between a top
surface of the first wall portion 231 and the circuit board 100 is
larger than a distance (h2) between a top surface of the second
wall portion 232 and the circuit board 100, and is not greater than
1.8 mm, wherein the second wall portion 232 is formed with a
plurality of positioning holes 234 that are spaced apart from each
other and that engage fittingly and respectively the positioning
pins 122 of the partition wall 12 of the metal frame 10. Each
positioning hole 234 is defined by an annular inner surface 235. It
is noted that the conductive material layer 22 is further attached
to the annular inner surfaces 235 of the top wall 23 of the cover
body 21 such that the conductive material layer 22 is further in
electrical contact with the positioning pins 122 of the partition
wall 12 of the metal frame 10.
[0021] As shown in FIG. 5, a conductive glue 30 is attached between
a top end 111 of the looped surrounding wall 11 of the metal frame
10 and the conductive material layer 24 of the cover 20, while a
conductive glue 30' is attached to the conductive material layer 22
of the positioning pins 122, and covers a corresponding one of the
positioning holes 234 in the second wall portion 232 of the top
wall 23 of the cover body 20.
[0022] FIG. 6 illustrates the second preferred embodiment of an
electromagnetic shielding device according to this invention, which
is a modification of the first preferred embodiment. In this
embodiment, since the cover body 21' is formed by injection
molding, the top wall 23' of the cover body 21' is formed so that
the first and third wall portions 231, 233 have a thickness (t1)
less than a thickness (t2) of the second wall portion 232'.
[0023] In sum, due to the presence of the conductive material layer
22, the conductive glues 30, 30', the electromagnetic shielding
device of the present invention can achieve an effective
electromagnetic shielding effect. Furthermore, since the cover body
21, 21' is dielectric, the top wall 23, 23' of the cover body 21,
21' can be designed to be very close to the electronic component
units 110, 120 or even contact the same without occurrence of short
circuit, thereby facilitating miniaturization of the electronic
device. On the other hand, since the cover body 21, 21' is formed
by injection molding, the cover body 21, 21' can be easily
fabricated to have desired height and thickness as required for the
electronic device.
[0024] While the present invention has been described in connection
with what are considered the most practical and preferred
embodiments, it is understood that this invention is not limited to
the disclosed embodiments but is intended to cover various
arrangements included within the spirit and scope of the broadest
interpretation so as to encompass all such modifications and
equivalent arrangements.
* * * * *